Sludge tank having a u-shaped conduit having arm portions inclined downward to the lower part of said tank and a conduit opening into said tank connecting said portions



-HAPMAN 2,432,756 SHAPED CONDUIT HAVING ARM PORTIONS INCLINED Dec. 16,1947.

SLUDGE TANK HAVING A U DOWNWARD TO THE LOWER PART OF SAID TANK AND ACONDUI'I' OPENING INTO SAID TANK CONNECTING SAID PORTIONS Filed Jan. 15,1944 3 Sheets-Sheet 1' n 2 a M \w ULHHHH. x Wil uhl hl hnl Ri n n E 17(Q 3 I w r u 2 I 2 IIIJ 4 3 w M 15% avg zi! Dec. 16, 1947. w, HAPMAN2.432.756

SLUDGE TANK HAVING A U-SHAPED CONDUIT HAVING ARM PORTIONS INCLINEDDOWNWARD TO THE LOWER PART OF SAID TANK AND A CONDUIT OPENING INTO SAIDTANK CONNECTING SAID PORTIONS Filed Jan. 15, 1944 3 Sheets-Sheet 2INVENTOR.

Dec. 16, 1947., w, HAPMAN 2,432,755

SLUDGE TANK HAVING A U-SHAPED CONDUIT HAVING ARM PORTIONS INCLINEDDovmwARD TO THE LOWER PART OF SAID TANK AND A CONDUI'I OPENING INTO SAIDTANK CONNECTING SAID PORTIONS Filed Jan. 15, 1944 3 Sheets-Sheet 3 I WWM SLUDGE TANK HAVING DUIT HAVING ABM AND INTO SAID TANK TIONS A U-BHAPEDGON- PORTIONS INCLINED THE LOWER PART OF CONDUIT OPENING CONNECTING SAIDPOR- Henry w. Hapman, Detroit, Mich. Application January 15, 1944,serum. 51am 14 Claims. (01. 210-55) The present invention relates toself-cleaning coolant tanks, and more particularly, to an apparatus forcollecting sludge and the like from said tank.

The primary object of the invention is to provide a self-cleaningcoolant tank in the system of a grinding machine or the like employing acoolant for reducing the temperature of the work while being ground andto provide a device which is portable and may be readily moved from onelocation to another adjacent the grinding machine.

Another object of the invention is to provide a, coolant tank of theabove-mentioned type having a sludge conveying and collecting systemiorcontinuously moving the sludge and other foreign matter in thecoolant liquid so that the coolant liquid may be recirculated to thegrinding machine. 1

Another object of the invention is to provide a self-cleaning coolanttank of the above-mentioned character which may be operated continuouslyor during intervals so "as to maintain the coolant liquid in a cleancondition and to prevent the collection of large quantities of sedimentin the bottom of the tank to. contaminate the coolant liquid.

Another object of the invention is to provide a self-cleaning coolanttank which is entirely automatic and requires very little attention onthe part oi the grinding machine operator so as to maintain the coolantliquid free of sediment and sludge collected during the grindingoperation.

Another object of the invention is to provide an inlet for the coolantliquid as it is discharged from the grinding machine directly above acompertinent formed by a bailie plate so that foam and the like may beremoved from the surface of" the liquid through an opening at one sideof the coolant tank directly opposite the inlet.

Another object of the invention is to provide a self-cleaning coolanttank of the above-mentioned character having a uniquely constructedsediment and sludge collector of the endless conveyor type which isadapted to travel a circuitous path and traverse the bottom 01' theself-cleaning coolant tank during a portion of said circuitous path.

Other objects and advantages of the invention will become apparentduring the course of'the following description of the accompanyingdrawings, wherein:

Figure 1 is a side elevational view of the cool-- ant tank embodying theinvention,

illustrating the same in position adjacent the centerless grindingmachine, and illustrating the manner in which the conveyor is arrangedto collect sludge and sediment from the tank and convey the same to apoint of discharge;

Figure 2 is a top plan view of the coolant tank showing the conveyordisconnected therefrom to illustrate the general shape and design of thecasing structure;

Figur 3 is a top plan view of the conveyor tubing illustrating thegeneral shape thereof and showing the reduced intermediate section forbeing welded to the sloping walls of the coolant tank so that the freeends may project upwardly to a point of discharge; 7

Figure 4 is an enlarged cross-sectional view illustrating the manner inwhich the. sloping walls of the coolant tank are welded to theintermediate portion 01' the'conveyor tube;

Figure 5 is a vertical cross-sectional view showing the discharge end ofthe conveyor tubes greatly enlarged, illustrating the manner in whichthe sludge and sediment is removed by the endless conveyor;

Figure 6 is a plan view showing in detail one of the conveyor flightsfor the conveyor illustrating the manner in which the same is cut outltoaccommodate the conveyor chain;

Figure 7 is a transverse cross-sectional view through the conveyor chainillustrating the manner in which the conveyor flights are bolted theretoby oppositely extending lugs on opposite sides of the conveyor chain;

Figure 8 is a cross-sectional view online 8-8 in Figure 1 showing thmanner in which the free ends of the conveyor tube are welded to aninterconnecting plate which is welded or otherwise fastened in place; I

Figure 9 is a top view greatly enlarged showing the manner in which themotor support and conveyor sprocket are adjustably supported adjacentthe free end of. the conveyor tube;

Figure 10 is a longitudinal sectional view on line lll-I|l in Figure 9looking in the direction of the arrows, illustrating in detail themanner in ner in which the sprocket 3 which'the adjustable motor andsprocket supporting plates are carried by the free ends of the conveyortubes; and

Figure 11 is an end elevational view of the adjustable motor supportingbase showing the manis supported for being driven by the motor on theunderside of said plate.

Brief description of the invention The invention broadly comprises atank having sloping bottom walls and battle partitions for the receptionof a coolant fluid circulated over the grinding wheels of a centerlessgrinder so as to cool the work during grinding. The coolant with theparticles of metal or the like is then returned to the tank and thesludge therein and other sediment is collectedin the bottom of the tankwhere it is adapted to be removed by an endless conveyor arranged andpositioned so as ,to convey the sludge and sediment to a point ofdischarge remote from the tank. In grinding machines of the centerlesstype, the coolant tank associated with the circulatory system becomesfilled with sediment and sludge to such an extent as to stop circulationof the coolant liquid and create obnoxious odors, and it is frequentlynecessary to remove the sludge and sediment by manual labor whichrequires the centerless grinding machine to be thrown out of operationuntil the removal of the sediment and sludge has been completed.

The above objections and disadvantages are overcome by providing auniquely constructed tank which may be presented to the discharge of thecenterless grinder so as to collect the coolant with the abrasive andother particles so that the particles will be collected at the bottom ofthe tank and discharged over a suitable receptacle which may be easilyemptied when full and thereby prevent the centerless grinder from beingout of operation over long periods of time and at the same time maintainthe coolant liquid in clear, clean condition. Another advantage inherentin the coolant tank embodying this invention resides in the fact thatfoam and the like may be removed from the tankfrom the liquid levelthereof adjacent the inlet opening of the tank so that said foam willnot overflow and cause objectionable odors and appearance.

Detailed description of the invention In the drawings, Figure 1 shows apreferred form of the invention comprising a collection and sedimenttank of rectangular construction having a pair of side walls 5 connectedat one end by an end wall I and at the other end by an end wall 8.Connecting the side walls 6 and welded or otherwise secured to thesloping edge 9 thereof is a sloping bottom wall ll (Figure 4). having adepending flange portion l2 and the extreme lower portion of the slopingbottom wall II is tapered inwardly at both ends as at IS. A slopingbottom wall l4 extends from the end wall 8 to a point adjacent the lowerend of the sloping wall H and said end wall is also provided with adepending flange l5 similar to the flange l2 and arranged in parallelrelationthereto. The sloping wall i4 is slightly reduced in width asshown in Figure 2 in dotted lines and is spaced from the side walls 6and the tapered portion l3 of the sloping wall as well as the reducedsloping wall II. A plate I1 is welded in place to the side wall 6adjacent each end or side of the reduced sloping bottom wall l4. Said-to the top edge of the side walls plates may be welded along the edgesto the reduced sloping wall l4 and may have extensions adjacent thelower portions provided with armately cut out areas to facilitate thepassage of the conveyor structure which will be hereinafter more fullydescribed.

A cover plate l9.is welded or otherwise secured 6 and end walls I and 8and said cover l9 terminates at one of its ends a short distance fromone of the walls 1 so as to provide a space therebetween, a portion ofwhich is adapted to be closed by a hinged closure 20 hinged to the topwall l9 as at 2|. The remaining portion of the opening is closed by aframe 23 having sloping walls 24 to form a framework for a screenedinlet 25. One endof the casing has its side wall 6 cut away as at 26 ata point near the liquid level of the coolant tank so that foamcollecting on the top of the liquid may be withdrawn or removed byscooping the same toward one end of the casing. The closure 20 isadapted to facilitate the replenishing of the coolant liquid and theaddition of various ingredients thereto from time to time. Extendingbetween the side walls 6 and terminating adjacent the sloping bottomwall I I is a partition 28 which extends downwardly from the edge of thetop wall l9 so as to form a compartment adjacent the entrance or coolantliquid inlet so that the heavier particles will be directed downwardlytoward the sloping bottom wall II when the coolant liquid is circulatedthrough the tank. Similarly, a partition wall 29 extends between thereduced sloping floor l4 and terminates at short distance from the topwall 19 and said partition interconnects the plates l1 and the end wall8 so as to form a chamber for the sludge and sediment in the tank. Thecoolant liquid passing through the tank is adapted to overflow thebaflie 29 at the top thereof as at 30 so as to fill a compartment havingtapering walls 3| and an end wall 32. The end wall 8 forms the otherwall of the liquid coolant chamber and completes the structure with thebottom wall 33 extending between the end walls 8 and 32. The top of theliquid coolant chamber on the left side of the tank is closed by a coverplate 34, and mounted on said cover plate is a circulatory pumpapparatus 35 including a motor and suitable gearing with the motor shaftextending downwardly through a tube 36 to a point adjacent the floor 33where it is connected to the rotor of a sump pump 31. The outlet side 38of the sump pump is connected by a tube or conduit 39 to a supply pipe40 the end of which is connected to the centerless grinder for supplyingthe coolant liquid to the wheels thereof. The sump pump 31 may be of thecentrifugal type and is provided with a centrally positioned inlet incommunication with the coolant liquid chamber to the left of the coolanttank.

Secured to the depending flanges 12 and iii of the respective slopingbottom walls II and I4 is a short length of pipe 4| (Figure 4)diametrically divided and cut away a distance equal to the space-betweenthe edges of the sloping wall l4. The depending flanges l2 and I5 arewelded as at 42 to the edge of the divided pipe to form a trough 43 ofsemi-circular shape. The ends of the semi-circular trough'43 are weldedto the plates l1 adjacent the openings therein so as to aid in spacingsaid plates. Elbow sections 45 are welded or otherwise secured to theouter sides of the plates l1 and the ends of the semi-circular troughportion 43, and said elbow fittings 45 are provided with relativelystraight portions 48 terminating in angularly disposed discharge andinlet ends 41 and 48 respectively. The extreme free ends of the pipes41' and 48 are flared outwardly as at 48 and 58 to allow the freepassage of the endless conveyor adapted to travel through the tubes 41and 48 and also traverse the semicircular trough 43. As shown in Figure1, the relatively straight portions 48, 41 and 48 of the conveyor tubesare angled with respect'to the horizontal and are inclined upwardly fromthe semi-circular trough 43 to a point of termination adjacent the top5. It is to be noted that the free end portions 41 and 48 extend alongthe side walls 3| of the coolant chamber and an angle bracket 52 iswelded to the end wall 32 of the coolant chamber for supporting thetubes 41 and 48 at each end thereof.

Mounted between the free projecting ends of the tubes 41 and 48 is asupporting plate 53 having obliquely cut edges 54 which are adapted tobe welded as at 55 (Figure 8) along the top of the conveyor tubes 41 and48. The plate 53 is adapted to hold the free ends of the conveyor tubestogether and to form a support for a motor sprocket drive including apair of spaced parallel bars 58 (Figure 9) bolted or otherwisefastenedto the plate 53 as at 51. The bars 58 project beyond the plate53 and bolted to the bars. 58 is a pair of similar bars 58 strips 58..Bolts 58 spaced by means of spacer are passed through the strips 58, 58and 58 and it is noted that the space between the strips 58 and 58 formsreceiving a sliding plate 8| having a lug at one end thereof as at 82 towhich is pivotally attached a screw-threaded shaft 83 by means of a,pivot pin or the like as at 64.. The screw shaft83 is received in anaperture formed in a, lug 85 connected with the plate 53 and suitablenuts 88 are mounted on the rod 63 in threaded relation therewith, and onopposite sides of the lug 65 to permit adjustment of the sliding plate6| along the ways provided by the spaced parallel bars 55 and 58.

Secured to the sliding plate 8| is an electric motor 88 having areduction gear casing 58 in the lower portion thereof and the shaft ofsaid reduction gearing is adapted to project through an opening 18 inthe plat 8| so as to be drivingly connected to a. sprocket wheel 1|suitably keyed thereto as by means of a ib and slot connection. A spacersleeve 12 is mounted on the shaft between a washer 13 on the undersideof the plate 8| and the sprocket 1| o as to space the sprocket asuflicient distance from the plate El and perwit the conveyorstructureto pass under. A switch 14 is provided on the motor 88 and saidswitch maybe connected with a domestic source of current to supply themotor 88.

Extending through the conveyor tubes 41. and

88 in the relativelystraight sections 46 and trained over the sprocket1| is a conveyor chain generally designated by the reference character15 comprising links 18 having alternate pivot pins 11' and. pivot pinsocket members 18. Each chain link 16 is provided with a pair ofoppositely extending wing-like lug members 18 projecting from oppositesides of said links in a lateral direction and the free ends of saidlugs are apertured for the passage of bolts 88 which bolts are adaptedto pass through the openings .8l'in the conveyor flight members 82(Figure 6). Nuts 83 may be threaded on, the bolts 88.'to retain thedisc-shaped flights 82 in place and said flights are backed by ag-uideway for a disc-like plate 84 to-add a certain amount of the upperwheel 1| as the flights pass therearound. It is to be noted that theconveyor flights 82 and backing plates 84 while being of difierentdiameters are shaped and formed so as to traverse the trough 48 andremove the sediment or sludge therefrom deposited from the tank 5.

The discharge conduit 41 is provided with a shield plate 88 welded orotherwise fastened in place as shown in Figure 5 and said shield plateis adapted to catch drippings from the flared end 48 and prevent thesame from flowing downwardly along theoutside of the conveyor tube 41.

The side walls 8 of the tank 5 are provided with vertical leg members 88while the end wall 32 of the coolant chamber is provided with an ad-Justable leg 88 having a foot portion 8| to facilitate the supporting ofthe less grinder generally indicated by the reference character G. Theleg 88 is adjustably held in place by means of bolts or the like as at82. A relatively large receptacle 83 may be positioned under thesprocket wheel 1|, discharge end of the conveyor tube 41 and directlybelow the depending lip 88 so as to catch the discharge' from the tank5'when the motor 88 is in operation, and facilitate the removal of thesludge and sediment therein from a, point remote from the tank.

The grinder G is typical of a conventional centerless grinder andembodies a base B having spindle supports C for rotatably mounting apair of grinding wheels D. The frame B is provided with an extensiontrough E directly beneath the grinding wheels D so as to catch andcollect the coolant liquid after the same has passed over the ma terialbeing ground between the grinding wheels D. A dischargeopening or spoutF is formed in the trough E and said discharge spout F is adapttrough Edirectly into the tank 5. After the coolant liquid passes into the tank'through the screened opening 25 it is caused to travel downwardlyadjacent the sloping floor II and under the baille 28 so that theheavier particles will be guided downwardly toward the semi-circulartrough 43. The coolant liquid will then pass over the top edge 38 of thebaflle wall 28 where it will enter the coolant chamber so as to berecirculated back to the grinder G by means of the centrifugal sump pump31 through the tube 48. The tube 48, generally a part of the grinder, iscoupled with end Of the discharge tube 38 and upon operation of themotor 35 circulation of the liquid will be effected. As the sludge orsediment c01- lects in the semi-circular trough 43 in the lower part ofthe sloping walls II and I4 it may be desired to remove the sludge so asto be collected in a receptacle 83. In order to remove the sludge. themotor 68 is started by manipulating the switch 14 so as to cause theconveyor chain to traverse the sprocket wheel 1| and pass through theconveyor tubes 41 and 48 so as to withdraw the sludge and sediment tothe outer flared end 48.

In addition to permitting the conveyor flight to pass around thesprocket wheel, the slots 88 allow the coolant liquid to return fromsuccessive flights as they reach the flared opening 48 and therebyprevent pumping of the coolant liquid and removal of the sludge S..

If desired, the pipe section 4| may be slightly tank adjacent a center-'smaller in diameter than the conduit sections 46,

41 and 48 so that as the conveyor flights traverse the semi-circulartrough 43, a relatively tight fit therebetween will be had whileconveyor flights travelling through the conveyor tubes 48, 41 and 48will be permitted a greater clearance so that the coolant liquid may runback from one flight to the other and prevent the same from being pumpedout of the discharge tube 41. It is also to be noted that the flared end49 of the discharge l0 tube 41 relieves the flights of any pumpingaction as they near the flared end by the greatly increased diameter of.the discharge pipe so as to further eliminate pumping of the coolantliquid as it travels toward said discharge.

When the conveyor 15, including the chain structure 16 and the flightelements 82, has become worn on one of their diametrical sides, theconveyor may be removed and reversed so as to bring the otherdiametrical side in contactual 20 wiping engagement with the tubes 84and the tubes 41 and 48 and trough 43. Since it is necessary to mountthe conveyor 1n the position reversed to its position shown in thedrawing during such a change, it is obvious that the motor 68 would haveto be reversed so as to change the direction of conveyor travel. In thisevent the discharge tube 48 would become the outlet and the tube 41 theinlet.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a preferred embodiment of the same and thatvarious changes may be made in the shape, size and arrangement of partswithout departing from the spirit of the invention or the 5 scope of thesubjoined claims.

What I claim is:

1. A sludge removal apparatus comprising a receptacle having adownwardly-sloping bottom wall, an approximately U-shaped conduit struc4n ture having tubular arm portions inclined downward to the lower partof said receptacle and a connecting conduit portion extending throughthe lower part of -said receptacle and interconnecting said armportions, said connecting portion hav- 45 ing an opening in the upperpart thereof for the passage of the sludge settling downward in thereceptacle, an endless conveyor mounted in said conduit structure andhaving a portion extending externally thereof, and power-actuateddriving mechanism drivingly engaging the external portion of said flightconveyor for moving said conveyor'through said conduit structure.

2. A sludge removal apparatus comprising a receptacle having. adownwardly-sloping bottom wall, an approximately U-shaped conduitstructure having tubular arm portions inclined downward to the lowerpart of said receptacle and a connecting conduit portion extendingthrough the lower part of said receptacle and interconnecting said armportions, said connecting portion having an opening in the upper partthereof for the passage of the sludgesettling downward in thereceptacle, an endless conveyor mounted in said conduit structure andhaving a portion extending externally thereof, and power-actuateddriving mechanism drivingly engaging the external portion of said flightconveyor for moving said conveyor through said conduit structure, saiddriving mechanism including a driving wheel mounted betweenandadiacentthe outer ends of said arm portions of said conduit structure and.drivingly engaging said conveyor.

3. A sludge removal apparatus comprising a receptacle having adownwardly-sloping bottom nal portion of said wall, an approximatelyU-shaped conduit structure having tubular arm portions inclined downwardto the lower part of said receptacle and a connecting conduit portionextending through the lower part of said receptacle and interconnectingsaid arm portions, said connecting portion having an opening in theupper part thereof for the passage of the sludge settling downward inthe receptacle, an endless conveyor mounted in said conduit structureand having a portion extending externally thereof, and power-actuateddriving mechanism drivingly engaging the exterflight conveyor for movingsaid conveyor through said conduit structure, said driving mechanismincluding a driving wheel mounted between and adjacent the outer ends ofsaid arm portions of said conduit structure and drivingly engaging saidconveyor, the lower portions of said flight conveyor being guided solelyby said conduit structure whereby to obviate guide wheels in saidreceptacle.

4. A sludge removal apparatus comprising a receptacle having adownwardly-sloping bottom wall, an approximately U-shaped conduitstructure having tubular arm portions inclined downward to the lowerpart of said receptacle and a connecting-conduit portion extendingthrough the lower part of said receptacle and interconnecting said armportions, said connecting portion having an opening in the upper partthereof for the passage of the sludge settling downward in thereceptacle, an endless conveyor mounted in said conduit structure andhaving a portion extending externally thereof, and power-actuateddriving mechanism drivingly engaging the external portion of said flightconveyor for moving said conveyor through said conduit structure, saidconduit structure having bends therein adjacent the junctions of saidarm portions with said connecting portion and said flight conveyordirectly engaging the inner walls of said bends for guidance andalteration of direction of travel.

5. A sludge removal apparatus comprising a receptacle having adownwardly-sloping bottom wall, an approximately U-shaped conduitstructure having tubular arm portions inclined downward to the lowerpart of said receptacle and a connecting conduit portion extendingthrough the lower part of said receptacle and interconnecting said armportions, said connecting portion having an opening in the upper partthereof for the passage of the sludge settling downward in thereceptacle, an endless conveyor mounted in said conduit structure andhaving a portion extending externally thereof, and power-actuateddriving mechanism drivingly engaging the external portion of said flightconveyor for moving said conveyor through said conduit structure, thelower part of said receptacle having openings in its opposite endsaligned with saidconnecting portion and said conduit arm portionsextending downward outside said receptacle and communicating with saidconnecting portion through said open- E- 6. A sludge removal apparatusfor reconditioning and recirculating coolant liquid for machine tools.comprising a receptacle having side and end walls connected bydownwardly sloping bottom walls and having an inlet forsludge-contaminated coolant liquid, said bottom walls converging attheir lower ends and terminating in an open-topped trough open at eachend, tubular conveyor tubes connected to the trough and extendingobliquely upward to the upper portion of saidreceptacle, a supportmounted at the free ends of said conveyor tubes, a sprocket joumaled onsaid support, a motor carried by said support and drivingly connected tosaid sprocket, an endless conveyor connected to said sprocket and passing through said conveyor tubes into said trough, and a pump incommunication with said receptacle at a location remote from saidcoolant liquid inlet and the trough for circulating said liquid to themachine tool.

-7. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for-machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom walls and having aninlet for sludge-contaminated coolant liquid, said bottom-walls.converging at their lower ends and terminating in an open-topped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion or said receptacle, asupport mounted at the free ends of said conveyor tubes, a sprocketjournaled on said support, a motor carried by said support and drivinglyconnected to saidsprocket, an endless conveyor connected to saidsprocket and passing through said conveyor tubes into said trough, and apump in communication with said receptacle at a location remote fromsaid coolant liquidinlet and the trough for circulating said liquid tothe machine tool, said conveyor having spaced apart flight membersadapted to remove sediment from said trough and convey the same to apoint remote from the receptacle.

8. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly slopin bottom walls and having aninlet for sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an opentopped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion of said receptacle, asupport mounted at the free ends of said. conveyor tubes, a sprocketjournaled on said support, a motor carried by said support and conveythe same to a point oi! discharge remote drivingly connected to saidsprocket, an endless conveyor connected to said sprocket and passingthrough said conveyor tubes into said trough, and a pump incommunication with said receptacle at a location remote from saidcoolant liquid inlet and the trough for circulating said liquid to themachine tool, said conveyor includ ing an endless chain having discshaped conveyor,

flights secured thereto adapted to remove sediment from said trough andconvey the same to a point exterior of said receptacle.

9. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bot-' tom walls and havingan inlet for sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an open-topped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion of said receptacle, asupport mounted at the free ends of said conveyor tubes, a sprocketjour- I naled on said support, a motor carried by said support anddrivingly connected to said sprocket, an endless conveyor connected to.said sprocket and passing through said conveyor tubes into said trough,and a pump in communication with said receptacle at a location remotefrom said coolant liquid inlet and the trough for circulating from saidreceptacle.-

10. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom walls and having aninlet for sludgecontaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an open-topped troughopen at each end, tu-

bular conveyor tubes connected to the trough and extending obliquelyupward to the upper portion of said receptacle, a, support mounted atthe free ends of said conveyor tubes, a sprocket journaled on saidsupport, a motor carried by said support and drivingly connected to saidsprocket, an endless conveyor connected to said sprocket and passingthrough said conveyor tubes into said trough,

and,a pump in communication with said receptacle at a location remotefrom said coolant liquid inlet and the trough for circulating saidliquid to the machine tool, at least one of said conveyor tubes havingits free end flared outwardly to prevent pumping of the liquid by saidconveyor.

11. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom Walls and having aninlet for sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an open-topped troughopen at each end, tubular conveyor tubes connected, to the trough andextending obliquely upward to the upper portion of said receptacle, asupport mounted at the free ends of said conveyor tubes, a sprocketjournaled on said support, a motor carried by said support and drivinglyconnected to said sprocket, an endless conveyor connected to saidsprocket and passing through said conveyor tubes into saidtrough, and apump in communication with said receptacle at a location remote fromsaid coolant liquid inlet and the trough for circulating said liquid tothe machine tool, said receptaclehaving partition walls to cause liquidfed to said receptacle to follow a sinuous path directly above saidtrough. 7

12. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom walls and having aninlet for sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an open-topped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion ant liquid irom saidmachine tool and direct the said support, amotor carried by samedownwardly into the vicinity of said trough.

13. A sludge removal apparatus for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom walls and having aninlet jor. sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an opentopped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion or said receptacle, asupport mounted at the free ends of said conveyor tubes, a sprocketjournaled on said support and drivingly connected to said sprocket, anendless conveyorconnected to said sprocket and passing through saidconveyor tubes into said trough, and a pump in communication with saidreceptacle at a location remote from said coolant liquid inlet and thetrough for circulating said liquid to the machine tool, a partition insaid receptacle separating said circulating pump from the remainder ofsaid receptacle and a motor drive mechanism on the top of the receptacleabove said pump for driving the same.

14. A sludge removal apparatus .for reconditioning and recirculatingcoolant liquid for machine tools, comprising a receptacle having sideand end walls connected by downwardly sloping bottom walls and having aninlet for sludge-contaminated coolant liquid, said bottom wallsconverging at their lower ends and terminating in an open-topped troughopen at each end, tubular conveyor tubes connected to the trough andextending obliquely upward to the upper portion of said receptacle, asupport mounted at the tree ends of said conveyor tubes, 9, sprocketjourn'aled on said support, a motor carried by said support anddrivingly connected to said sprocket, -an endless conveyor connected tosaid sprocket and passing through said conveyor tubes 12 into saidtrough, and a pump in communication with said receptacle at a locationremote from said coolant liquid inlet and the trough for circulatingsaid liquid to the machine tool, said receptacle having in its upperportion at one side thereof a foam removal opening whereby to facilitatethe removal of foam from the receptacle.

HENRY W. -HAPMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

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